JPS62144071A - automatic chemical analyzer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is directed to II! Regarding IJ analyzers, it is particularly suitable for analyzing items that require periodic calibration and re-creation of calibration curves, such as items where the properties of reagents and sensors tend to change over time. Regarding chemical analysis equipment.

[Conventional technology]

Automation of clinical biochemical tests has progressed, and automatic biochemical analyzers have also made great progress in recent years. Along with this, a high level of analytical precision is now required7. Although the accuracy of automatic analyzers is much higher than that of conventional manual methods, it is important to consider how to maintain this high level of accuracy. In reality, there are large accuracy differences even between machines of the same model. This is because error factors specific to routine analysis using automatic analyzers are involved. There are various causes of errors in daily analysis using an automatic analyzer, and one of the major causes of analysis errors is deterioration of reagents. Reagents are highly likely to change depending on usage conditions such as storage temperature, amount used, container color, and degree of sealing. However, even if an abnormality occurs, it is difficult to predict unless it is completely inactivated, so no consideration was given to errors caused by deterioration of the reagent.

[Problem that the invention seeks to solve]

As the reagent changes over time, the absorbance of the reagent blank also changes, but conventional automatic analyzers only perform calibration to create the calibration curve necessary for analysis before starting the analysis. There was a problem in that it did not take into account changes in absorbance, which affected analysis accuracy.

The purpose of the present invention is to eliminate errors caused by changes in this reagent over time,
The object of the present invention is to provide an automatic chemical analyzer that can obtain more accurate analysis results.

[Means for solving problems]

In automatic chemical analyzers, errors due to changes in reagents over time affect the accuracy of analysis results, but calibration is periodically performed at regular intervals to account for changes in absorbance due to changes in reagents over time, and a calibration curve is re-created. As a result, an improvement in analysis accuracy is achieved.

[Operation] In analysis using an automatic biochemical analyzer, calibration is performed periodically at regular intervals during analysis. As a result, the calibration curve that serves as the reference value for the analysis results is rewritten, so that the change in absorbance is corrected. Figure 7 shows the calibration curve obtained by calibration before the start of analysis and the calibration curve obtained by calibration performed during analysis.
Show the line.

The calibration curve 50 is before the start of analysis, and the calibration curve 51 is during analysis. When the concentration is determined from the absorbance Ax obtained by the analysis using a calibration curve, the concentration CX is 1. The calibration curve obtained by performing calibration during analysis has a concentration Cxz, and if the reagent changes rapidly over time, the difference between Cal and Cx1 becomes large. By recreating the calibration curve during analysis, reference values corresponding to the actual analysis can be obtained, and accurate analysis results can be obtained.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments. 1st
The figure is a configuration diagram of an automatic chemical analyzer that is an embodiment of the present invention. This device has a reaction table 21 equipped with a plurality of reaction vessels 1 (hereinafter referred to as measurement cells) around the circumference, a sample disk 4 on which a sample cup 3 containing the serum to be analyzed is placed, and a sample disk 4 for dispensing the serum. sample probe 7, which is a mechanism for the analysis, a reagent bottle 6 containing reagents necessary for analysis, a reagent disk 5 on which the reagent bottle 6 is placed, and a reagent probe 8, which is a mechanism for dispensing the reagent. Stirrer A1 for mixing the dispensed serum and reagent in A1. all
A light source lamp 11 that supplies the light necessary for measurement, a photometer 11 for photometry, a cleaning mechanism 10 for washing the dirty measurement cell 1 after the measurement is completed, and a system for inputting analysis conditions. Operation panel 13, CRT 14 for displaying input analysis conditions and analysis results. and a microcomputer 15 as a control device.

The analysis process of this device is carried out according to the following procedure.

First, input the analysis conditions before starting the analysis. The analysis conditions are input by keyboard input from the operation panel 13 while looking at the CRT 14.

When analysis conditions are set and instructions for analysis are input, the microcomputer 15 causes each mechanical section to perform an analysis sequence operation in accordance with the input analysis conditions. First, the measurement cell 1 is washed several times by the washing mechanism 10, and then comes to a position where serum is dispensed in a clean state without any contaminants remaining in the cell. A certain amount of serum is aspirated from the sample cup 3 on the sample disk 4 by the sample probe 7 and discharged into the measurement cell 1. The sample cup 3 containing the serum to be dispensed is placed at a predetermined position on the sample disk 4 registered at the time of inputting the analysis conditions. The sample cup 3 is rotated by the rotation of the sample disk 4 before the sample probe 7 aspirates the serum.
The serum is transferred to a position where it can be aspirated. This feeding of the sample cup 3 is repeated every time the sample changes in the order of analysis. The ill'l standard cell 1 containing serum is then conveyed by rotation of the reaction table 2 to a reagent dispensing position. A specified amount of the reagent is sucked by the reagent probe 8 from the reagent bottle 6 on the reagent disk 5 and discharged into the measurement cell 1. Transfer of the reagent bottle 6 to the reagent suction position is performed by rotating the reagent disk 5, as in the case of serum. The serum and reagents mixed into the measurement cell 1 are stirred by a stirrer 4it9.
The reaction proceeds for a certain period of time after stirring. During this time, the reaction table 2 rotates, and the absorbance is measured every time the measurement cell 1 passes between the light source lamp 11 and the photometer 12. The measurement cell 1, which is used to obtain analytical values from the measurement of the reaction results, is cleaned again by the cleaning mechanism 10 and used again for measurement. This series of processes is repeated as an analysis cycle.

The measurement cells 1 on the reaction table 2 are sequentially used for measurement.

Next, a method for calibrating this device will be described, and the periodic implementation of calibration (hereinafter this method will be referred to as cyclic calibration) is the details of the present invention.
I will explain about it.

Before starting analysis, this device creates a calibration curve that serves as the standard for measured values. This is called calibration. FIG. 2 shows the process of creating a standard curve through calibration and the progress up to concentration calculation. The absorbance is plotted on the vertical axis and the concentration is plotted on the horizontal axis, and the absorbance AL and As of standard solutions of Cb and Cs with known sensitivities are measured. A calibration curve is created from the two measurement points 21 and 22 obtained as a result of the measurement.

If the measured absorbance of the specimen is Ax, 1 degree Cx is obtained according to this calibration curve. Expressing this as a formula, the calculation method is as follows.

Cx = K (A x A b ) + Cb
(1) A s - A b Here, K is the slope of the calibration curve, and is determined by equation (2) as the ratio between the concentration difference and the absorbance difference between the two standard solutions. The concentration Cx of the specimen is calculated from the absorbance Ax of the specimen using equation (1). However, in this method, for example, when a reagent that changes rapidly over time is used, as long as a calibration curve is created first, an error will occur between the reference value and the actual value, making it impossible to obtain accurate measurement results. Therefore, we considered recreating the calibration curve at regular intervals.

The cyclic calibration of this device will be explained below.

FIG. 3 shows the set position of the specimen on the sample disk 5 of FIG. N1 to N40 are serum positions of general patients, Sl
From S30 is the standard solution position for calibration, and from CL to 06 is the control a for accuracy control of measured values.
- Le serum position, El to EIO are the emergency patient's serum positions. For example, FIG. 4 shows the order of analysis with and without performing cyclic calibration by sequentially analyzing serum N1 to N40 of general patients one item at a time. FIG. 4(a) shows a case without cyclic calibration, using standard solutions at positions 81 and 830. First, standard-1 solutions S1 and 830 are measured to create a calibration curve, and then serum samples from general patients are analyzed in order from N1. FIG. 4(b) shows a case where cyclic calibration is required, and it is specified by inputting the analysis conditions to perform calibration every three samples. First, the standard solutions of Sl and 330 were dispensed, and then the general patient's blood t1"
After dispensing 3 samples, the standard solutions S1 and S30 were changed to 1 again.
Ill+ is determined and the calibration curve is re-created.

Thereafter, the standard solution is measured every time a general sample is analyzed a certain number of times, and accurate analysis results are obtained.

The calibration interval is the number of specimens, and in addition to general patient sera N1 to N40, emergency patient sera E1 to EIO and control sera C1 to C6 are also counted as the number of specimens in the calibration interval.

Input for performing cyclic calibration in this apparatus is performed on the analysis item selection screen shown in FIG. The calibration format 3o is an input section for selecting whether to perform the calibration before starting the analysis or periodically, and if it is [CYCLIC], the latter calibration is selected. Input section 31
is where the interval of cyclic calibration is specified [If it is 1003, calibration will be performed every 100 samples. The input section 32 is an input position for analysis items. This device performs multi-item analysis.

Since the analysis item input section 32 allows selection of a single item, cyclic calibration can be specified on an item-by-item basis. If analysis is performed under the conditions shown in FIG. 5, calibration will be performed for every 100 samples for the analysis item CO2.

Cyclic calibration, which is the details of the present invention, will be explained using a flowchart with reference to FIG. First, when setting analysis conditions, if cyclic calibration is to be performed, an interval value for cyclic calibration is input in step 40. If a number other than O is input to the cyclic calibration interval input section 31 in FIG. 4, cyclic calibration is performed. 41 to 45 in FIG. 5 are one cycle of analysis, and if it is determined that calibration is required at 41, calibration information is set at 42 and measurement is performed. If it is determined in step 41 that there is no calibration, then in step 43 analysis information for the specimen of a general patient is set and measurement is performed. In the case of cyclic calibration, the information on whether or not calibration is performed, which is determined in step 41, is set for each interval value. In other words, analyze the serum of general patients for the number of samples entered, and after analyzing only the interval values, set the calibration to 1.
The test will be carried out twice, and samples from general patients will be analyzed again. If all analyzes have been completed, it is determined in step 45 that the analysis is complete, and the process ends. Cyclic calibration is performed through such a series of processes.

〔Effect of the invention〕

According to the present invention, the value of the calibration curve, which serves as a reference for serum measurement, is corrected for changes over time in reagents and sensors, so there is an excellent effect that accurate measurement values can be obtained over a long period of time.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of an automatic chemical analyzer that is an embodiment of the present invention, Figure 2 is a diagram for creating a calibration curve by calibration, Figure 3 is a diagram showing the sample setting position on a sample disk,
Figure 4 is a diagram showing the types of analyzes with and without cyclic calibration, Figure 5 is a diagram showing the analysis item selection screen, Figure 6 is a flow chart showing the procedure of the present invention, and Figure 7 is a diagram showing the analysis types with and without cyclic calibration. It is a figure showing the effect of click calibration. DESCRIPTION OF SYMBOLS 1...Measurement cell, 2...Reaction table, 3...Sample cup, 4...Sample disk, 5...Reagent disk, 6...Reagent bottle, 7...Sample probe, 8...・Reagent probe, 9... Stirring mechanism, 10...
・Cleaning mechanism, 11・Light source lamp, 12...Photometer, 1
3...Operation panel, 14...CRT, 15...Microcomputer.

Claims (1)

[Claims] 1. A sample disk with multiple measurement cells and multiple cups containing serum, calibration standard solution, and cleaning solution to be dispensed into the measurement cells, its dispensing mechanism, and measurement containing serum. The automatic chemical analyzer is equipped with a mechanism for dispensing reagents into a cell for analysis, an operation panel for inputting analysis conditions, a CRT for displaying the input analysis conditions and analysis results, and a computer for controlling the above-mentioned equipment. At this time, the calibration for creating a calibration curve is performed according to the cycle interval inputted from the operation panel and CRT.
An automatic chemical analyzer characterized in that a calibration curve is automatically recreated by performing periodic analysis only on selected items.